In this Part -

"cohabitant" has the meaning assigned to it in section 172;

"court" means the High Court, the Circuit Court or the District Court;

"dependent child",  in relation to a cohabitant or a couple of cohabitants, means any child of whom both the cohabitants are the parents and who is - (a) under the age of 18 years, or (b) 18 years of age or over and is - (i) receiving full-time education or instruction at any university, college, school or other educational establishment and is under the age of 23 years, or (ii) incapable of taking care of his or her own needs because of a mental or physical disability.